Bump JetBrains.Annotations from 2021.2.0 to 2021.3.0

Bumps [JetBrains.Annotations](https://github.com/JetBrains/JetBrains.Annotations) from 2021.2.0 to 2021.3.0.
- [Release notes](https://github.com/JetBrains/JetBrains.Annotations/releases)
- [Commits](https://github.com/JetBrains/JetBrains.Annotations/commits)

---
updated-dependencies:
- dependency-name: JetBrains.Annotations
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

src/Directory.Build.props

@@ -25,7 +25,7 @@
         <PackageVersion_LibGit2Sharp>0.27.0-preview-0116</PackageVersion_LibGit2Sharp>
         <PackageVersion_LibGit2Sharp_NativeBinaries>2.0.314</PackageVersion_LibGit2Sharp_NativeBinaries>
 
-        <PackageVersion_JetBrainsAnnotations>2021.2.0</PackageVersion_JetBrainsAnnotations>
+        <PackageVersion_JetBrainsAnnotations>2021.3.0</PackageVersion_JetBrainsAnnotations>
         <PackageVersion_YamlDotNet>11.2.1</PackageVersion_YamlDotNet>
         <PackageVersion_MicrosoftExtensions>5.0.0</PackageVersion_MicrosoftExtensions>
         <PackageVersion_MicrosoftJson>5.0.0</PackageVersion_MicrosoftJson>